The invention relates to a belt holder device comprising a housing having a first fixing device, a plate having a second fixing device and being mounted on the housing for displacement in a displacement direction, wherein the belt holder device is held on an application via one of the fixing devices and a belt is held on the other fixing device, a transmitter-sensor device which is arranged in the housing and by means of which the relative position of the plate to the housing can be determined, and a spring device via which the plate is supported on the housing and which provides a return force.
U.S. Pat. No. 6,729,194 B2 discloses a seat belt tension sensor device including a housing having an interior space. An anchor plate is provided having a recess to which a magnet is fixed, the magnet moving as the anchor plate moves and the magnet further being guided by a carriage mounted on the housing. A magnetic field sensor is mounted on the housing at a position below the carriage, the carriage protecting the sensor.
A further seat belt tension sensor device is known from U.S. Pat. No. 7,222,545 B2.
DE 100 50 551 A1 discloses a device comprising seat belt webbing for restraining an object in a vehicle seat, a sensor associated with the vehicle seat for sensing a sensed weight of the object in the vehicle seat, a seat belt tension sensor for sensing the tension in the seat belt webbing and a control device for determining a computed weight of the object as a function of both the sensed weight and the tension in the seat belt webbing.
DE 103 22 700 A1 discloses a belt buckle housing having an integrated force measuring device for measuring a belt tensile force acting on a belt buckle, including a movable anchor that protrudes through an opening formed in an end wall of the housing and has a stop which restricts the anchor's capability to move out of the housing against an elastic support operating between the housing and the anchor, and a sensor attached to the housing for sensing the position of the movable anchor.